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Applied Optics

Applied Optics


  • Editor: James C. Wyant
  • Vol. 46, Iss. 18 — Jun. 20, 2007
  • pp: 3736–3746

Sub-diffraction-limited multilayer coatings for the 0.3 numerical aperture micro-exposure tool for extreme ultraviolet lithography

Regina Soufli, Russell M. Hudyma, Eberhard Spiller, Eric M. Gullikson, Mark A. Schmidt, Jeff C. Robinson, Sherry L. Baker, Christopher C. Walton, and John S. Taylor  »View Author Affiliations

Applied Optics, Vol. 46, Issue 18, pp. 3736-3746 (2007)

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Multilayer coating results are discussed for the primary and secondary mirrors of the micro-exposure tool (MET): a 0.30 NA lithographic imaging system with a 200   μm × 600   μm field of view at the wafer plane, operating in the extreme ultraviolet (EUV) region at an illumination wavelength around 13.4   nm . Mo∕Si multilayers were deposited by DC-magnetron sputtering on large-area, curved MET camera substrates. A velocity modulation technique was implemented to consistently achieve multilayer thickness profiles with added figure errors below 0.1   nm rms demonstrating sub-diffraction-limited performance, as defined by the classical diffraction limit of Rayleigh (0.25 waves peak to valley) or Marechal (0.07 waves rms). This work is an experimental demonstration of sub-diffraction- limited multilayer coatings for high-NA EUV imaging systems, which resulted in the highest resolution microfield EUV images to date.

© 2007 Optical Society of America

OCIS Codes
(220.0220) Optical design and fabrication : Optical design and fabrication
(220.3740) Optical design and fabrication : Lithography
(240.5770) Optics at surfaces : Roughness
(310.0310) Thin films : Thin films
(340.7440) X-ray optics : X-ray imaging

ToC Category:
Thin Films

Original Manuscript: November 14, 2006
Revised Manuscript: February 6, 2007
Manuscript Accepted: February 7, 2007
Published: May 31, 2007

Regina Soufli, Russell M. Hudyma, Eberhard Spiller, Eric M. Gullikson, Mark A. Schmidt, Jeff C. Robinson, Sherry L. Baker, Christopher C. Walton, and John S. Taylor, "Sub-diffraction-limited multilayer coatings for the 0.3 numerical aperture micro-exposure tool for extreme ultraviolet lithography," Appl. Opt. 46, 3736-3746 (2007)

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